Even by the squeamish standards of the American media, the photographic record of the war in Iraq is remarkably antiseptic. The paradigmatic images are not of combat or of bodies in the street but, rather, the digital snapshots taken by US soldiers of Iraqi prisoners being humiliated at Abu Ghraib - that is, a consequence of war rather than the thing itself.

To an extent not appreciated by the public, the shortage of photographs depicting the dead and dying is not an accident. This past Saturday, the New York Times reported on the plight of Zoriah Miller, a freelance photographer who was banned from covering the Marines because he posted several photos of their dead bodies on his website. Miller, the Times added, is hardly alone in being pressured not to show the world anything too graphic.

Questions about war photos are as old as photography itself. More than a century ago, Mathew Brady and other photographers shocked a nation with their images of dead soldiers in the American civil war.

More recently, it has become an article of faith on the political right that grisly images of the Vietnam war - including the famous pictures of a street-side execution and of a naked young girl running from a napalm attack - undermined public support and led to the American defeat. Subsequent administrations have made it increasingly difficult for journalists to cover war in all its horror.

That effort has reached its nadir during the presidency of George Bush. And though its roots lay in the White House's desperate attempts to maintain some level of support for its failed policies, its censorious campaign is now being waged on behalf of Bush's preferred successor, John McCain. Unpopular as the war is, it would be more unpopular still if the public could truly see it.

Think back to the early, triumphant days of the Iraq war, leading up to the "Mission Accomplished" fiasco. War was reduced to a video game, with action figures racing through the desert and streaks of light aimed toward Baghdad. Once the insurgency began, the war became so dangerous for journalists to cover that they became dependent on the American military units with which they were embedded - a very different scenario from Vietnam, where reporters and photographers were able to operate with little interference.

More than 4,000 American troops have died to protect their country from Saddam Hussein's non-existent weapons of mass destruction, but you'd never know it from the nightly news. In a break with longstanding tradition, the White House even banned the media from observing the flag-draped coffins of dead soldiers when they arrive at Dover Air Force Base, in Delaware.

Contrary to conventional wisdom, bloody images of war do not necessarily undermine public support. I recently had an opportunity to view newsreel footage from the second world war, and a silent clip from the first world war, that were astonishingly graphic in their depiction of violence suffered by both the good guys and the bad guys.

The difference is that the second world war, especially, enjoyed near-universal popular support. Terrible images of troops felled in a war for survival only toughened the national resolve. Images of dead American troops in Iraq, by contrast, would - like those pictures from Vietnam - only serve to deepen public anger.

Just before I wrote this, I paged through a book of Iraq war photos by Ashley Gilbertson called Whiskey Tango Foxtrot. Gilbertson, whose pictures have often appeared in the New York Times, is not one to indulge in violence for violence's sake. There is as much blood and death in the brief slide show of Zoriah Miller's work as there is in all 264 pages of Gilbertson's book.

Still, Gilbertson's images are difficult to look at because they are so real. His is not the Iraq of General David Petraeus, Prime Minister Nouri al-Maliki and the surge-emboldened Sunni Awakening. Rather, we see courageous American troops, terrified civilians and an oppressive, overwhelming sense that it's all going to end badly. Gilbertson closes with the 2005 Iraqi elections, itself a bittersweet victory. He, and we, know that some of the worst violence occurred later on.

As it occurs still. On Monday, at least 53 people were killed and another 240 wounded in separate suicide attacks in Baghdad and Kirkuk. McCain can repeat "the surge is working" as much as he likes. Iraq remains an incredibly dangerous and fragile country.

Interviewers frequently ask Barack Obama if he'll admit he was wrong about the surge, but they rarely ask McCain if he was wrong about the war. In large measure that is because the American public cannot see the full consequences of this tragic mistake - a mistake that McCain supported from the beginning.